1. Field of the Invention
The present invention relates to a liquid level detecting device.
2. Description of the Related Art
Liquid level detecting devices for detecting a level of liquid stored in a tank are equipped with a device main body having a Hall element, a holder in which a magnet is provided so as to be rotatable with respect to the device main body, a float arm whose base portion is attached to the holder, and a float that is attached to a tip portion of the float arm (refer to JP-B-5176997, for example).
In liquid level detecting devices of the above kind, the float arm swings following the surface of liquid and the holder rotates with respect to the device main body. The Hall element provided in the device main body detects a variation of the magnetic flux generated by the magnet and a liquid level is detected on the basis of a result of the detection of the magnetic flux variation. In liquid level detecting devices of this type, the float arm is fixed to the holder and the rotation angle range of the holder is restricted in such a manner that a tip portion of a bent portion, closer to its base-side end than the position on it where it crosses the rotation axis of the holder is, of the float arm comes into contact with a restriction member.
Incidentally, in liquid level detecting devices having the above configuration, at the time of, for example, assembling, there may occur an event that the float arm comes into contact with a nearby member and the tip portion of the bent portion of the float arm comes into contact with a restriction member (stopper) of the device main body with a strong force. In this case, a heavy load acts on a float arm fixing portion of the holder, as a result of which the float arm may come off the holder or support portions that support the holder rotatably or other portions may be deformed. If the float arm fixing portion or the holder support portions are reinforced so as to be able to endure such a heavy load, resulting complication in structure would cause a cost or size increase.